Plaster-board.



E. T. GALLEY.

PLASTER BOARD.

APPucATIoN man 1m31, 1914.

Patented J une 19, 1917.

f l lIIIIIIIII ELMER T. GALLEY, or HUNTINGTON PARK, CALIFORNIA. v

i MASTER-BOARD'.

Spec'ication of Letters Patent. Patented June 19,' 191.7.

'Application tiledV January 31, 1914..' Serial No. 816,130.

Te all whom z't may concern Be it known that I. Emma T. GALLEY, a'

'citizen .of the United States, residing at Huntington Park, in the county 'of' Los Angeles and State of California, have invented a new and useful Plaster,-,Board, of -which the following is a specification.

This invention relatesto the manufacture -of boards that are applicable in the con? struction of buildings "tolform parts of the walls and ceilings thereof, that are capable of directly forming the exterior surfacesof walls and that vare more particularly de-4 I signed to be covered with plaster for formor outside the building.

ing the impervious wall faces either inside An object ofthe invention is to produce a light, strong and cheap substitute for wood and metal lathing and' to provide a board forming a substitute of this character which will be impervious to moisture and which will 4form a good insulator in' 'addition to forming a more or less tire-proof board uponwhich plaster may' be applied and which is so constructed that the plaster will -clench therein with superior bondand with a savl ing of plaster as compared with usual forms of open lathing of wood or metal,

An object 'is to provide a plaster board which can be readily fastened vto metal building structures in a practically {irep'roof manner. Y

Further objects and advantages may appear from the subjoined detail description.

VThe invention may be understood by reference to the accompanying drawings.

Figure 1 is a perspective fragmental view of a plaster boardconstructed in accordance with this invention. f

Fig. 2 is a section on line m2, Figs. 1 and 4. Fig. 3 is a perspective fragmental view of a plaster board showing a back plate spe cially equipped for the ceiling.

` Fig. 4 is a section on line m4, Figs. 1 andz2.

Fig. 5 isa fragmentalview of a plaster board constructed without reinforcements.

Fig. 6 is afragmentalperspective view of a mold for forming a plaster board.

Fig.` 7 is a section of a fragment of the mold with a plaster board formed therein.` The section is on line'indicated at m2, Figs. 1 and 4r.A

Fi 8 is a section of a plaster board secure 'by nails to joists, said plaster board having plaster secured thereto.

This novel plaster board comprises a cementitious base or body 1 and two vface plates 2 and 3, one of said face plates 2 con-'- stituting a perforated form sheet having de. pressions, said sheet -beingslitted and lindented, the other face plate, or more properly back plate3, beingsmooth and flat, and the cementitious base or body conforming to and adhering to the inner sides of the face plates 2 and 3 and having depressions extending to' bottoms within the base, said depressions registering with said perforations. Alternate intermediate portions betweenthe parallel slits in the face plate 2 are indented' forming openfsided ,indentations with tongues 4, integral'with the form sheet and v which recede. from the outerside of the face plate 2 and project from the inner side of.

said face plate, said indentations forming inserts in the body 1. The indentations or inserts at 4 owing to ,the provisionv of the slits have free longitudinal edges spaced apart from the edges of the intermediate portions so that plaster can enter sidewise through the slits and come into Acontact with exposed portions of the cement body 1 so as to-l strongly adhere thereto. The face plate 2 of the plaster board with its indentations forms a-clenching1 surface t0 which vplaster when applied will readily adhere, While the face plate 3, being smooth and fiat, forms a neat finish for the other side of the plaster board.

A board: thus constructed is light, strong, rigid and -impervious and can be fastened in place, for instance, by nails a., Fig. 8, driven through the plaster boardinto afsuppo'rt l) ada ted to receive the same. In finishing a wal or ceiling ofva building, plaster may be applied in the usual manner of 4plastering and .the samewill enter the indentations 4- and vpass through the slits into the sides of undercut, dovetail mortises or Awedge-shaped cavities 5 in which the indentations are ac- ,l

commodated, said mortises being expanded at their bottoms land contracted at their inlets, so that the clenchers of plaster will be positively retained thereby. Thus it is seen that the portions of the body 1 between adjacent cavities 5 form dovetail or wedgeshaped keys.

The face and. back plates 2, 3, mayl be made of any. suitablematerial to-which the body may be applied. I have successfully used tarred paper for the Plates and cement plaster for the body and I contemplate in some `in stances the use of asbestos paper or any iireproof material for the plates, and

any plastic that hardens may be used to form the body. It is preferable in the economy ofv manufacture that quick setting cement be 'used for the body.

A valuable feature of this invention is .de-- pendent upon slitting` the face plate and indenting the portion between the parallel slits for thereby the cement or plaster body of the plaster board is exposed at said slits and indentation, and when the plaster'board is in place as in ceiling work and a coating of wet plasterl is applied, such wet plaster will adhere to the exposed plaster or cement of the plaster boardwith greater suction and l with less possibility of slipping out of the indentations than would be the case if said2 wet plasterdid not come in direct contact with such cement body. Furthermore all danger of slippage from softening of the paper is avoided at these particular exposed portions, thus holding the wet plaster coating firmly until it is dried.

Furthermore I am not aware that there has yet been provided a construction of plaster board in which dove-tail recesses or depressions have been provided or suggested for the purpose of holding the plaster coating subsequently to be applied.

It is also desirable for fire and earthquakeproof buildings that the board be appropriately reinforced and with this object in view and' a further object of providing fastening means which can be applied to the supporting structure to holdthe board in place without making perforations therein, this reinforcement may readily be appliedin a practical way by placing wires in the place to be filled with the plaster or cement body. Plaster boards made of certain compositions of cement would crack if a nail were attempted to be driven through them, due to the unyielding character of such cement. When made-of such compositions of cement, the plaster boards are provided with fastening means that are formed embedded in the cement whereby the danger of cracking is removed. j Said fastening means may also be applied with any character of cement.

In Figs. 1 and 2 galvanized iron or steel wires 6, 7 and 8 are shown arranged crisscross in the body 1, the Wires 6 being threaded through the slitted and indented sheet and passing through the slits between pairs of wires T and pairs of loops 9`of said' face plate; the wires S'extending -transversely of the wires 6 and 7. The wires G hold the indented portions 4 against the bottoms of the mortises 5, thus maximizing the bonding effect between the body and the face plate. In Fig. 1 all the wires are shown as having their terminals projecting beyond the edges of the board.

, The embodiment shown in Fig. 3 Ends special utility when the plaster boards are usedfor a ceiling. The terminals of certain meeneeof the wires in this embodiment are shown as projecting from the back plate of the plaster board sowas to be in position to be fastened to the ceiling joists whereby the plaster boards are properly secured in position.

The terminals may be variously constructed, in some instances, extending freely to be wound or twisted around parts of the securing structure, as the terminals of the wires 6 and 8 projecting from the edge of the plaster board and the terminals of the wires 7 projecting from the back plate of the plaster board as'shown in Fig. 3, and in other cases being formed into eyes, as the eyes 10 of the wires 7 in Fig. 1.

The method of constructing the plaster board is as follows:

' First, the face plate 2 is provided with the slits and indentations. In the case of tarred paper the slits and indentations are formed at one operation while such paper is in a softened condition, such condition being effected by heating the forming instruments. Preferably the indentations may be made by passing the paper between heated rolls of suitable conformation to produce the slits and indentations. Said indentations Aare preferably semi-cylindric or curved segments thus giving an arched form to the plaster that will lodge therein.

The arched form of the plate thus formed increases the strength of the completed board as compared with a board made with only flat face plates; and when it is desired to use the reinforcing wires such wires may be threaded through the loops formed by the indentations. s

When the sheet or plate has thus been slitted and indented it is then laid on the bottom of the mold 12 which is provided with cylindric projections 13 that are preferably provided at their crowns with notches 14 to receive the wires 6 that have been threaded through the slits.

The projections 13 are arranged in pairs each having one'smooth side 11 which is opposite to and faces the smooth side of its companion projection and each having an outer inclined receding side 15 which is parallel to the smooth sides; the smooth sides being adapted to accommodate the projection 16 of a wedge 17, and the inclined receding sides 15 being provided to form, the undercut portions 5 in the indentations 4.

, The sides 18 of said mold are-provided with vertical slits 19 and 20, the openings or perforations formed by the slits 19 being alined with the notches 14 so that wires 6 will rest in the notches and have their terminals resting in the slits 19, the openings or perforations formed by the slits 20 being located intermediate those formed by the slits 19 to accommodate the terminals of the wires 7. Preferably the wires 8 are laid under and transverse to the wires 6 and 7 y at one side'. of the perforations formed at the depressions between the slits, and lying betweenthe rows of projections 13, and the terminals of said Wires may be accommodated in the openings or perforations formedby slits 21 provided in ,the ends 22 of said mold, theslitsv 21 being vcut deeper than the slits-20 for the purpose just described.

. suitable means, not shown, to solidly com- -When the face plate and the wires'are thus arranged a plastic cement body, which may be of any suitable material that will adhere tothe faceplate and willharden, is

press the back platel 3 onto the plastic body and to compress such body against the face4 plate 2, thus forcingv the plastic massto conform to and adhere to the face plate and the wires.' The pressure is then `removed and the plaster board having become set is removed and stored for seasoning.'

cementitious material of thebody exposed.

conserved.

Ihe tongues 4 are integral with the form sheetl or face 4plate v2 and attachedithereto along the bottoms of the body depressions in the cementitious base so as to coverthe bottoms of the depressions and leave the on, the sidesof the'depressions. By forming the tongues 4 of strips between slits and eX- tending the tongues the "full llength of their respective depressions and having them con- =nected` to the sheet 2-at both sides of the perforations, strength 4of the finished board is When the modification shown in Fig. 3 is being molded, before-putting the back plate 3 in place and applying pressure, terminals of certain ofthe wires, as forinstance the wire 7', are extended up from the mold.

Then in' the same manner just described with the other modiication, the back plate 3`is placed lon top of the plastic body, it having openings 24 provided to accommodate the upwardly extending terminals of theA wire 7 'and then the pressure plate 23 forced down upon saidback plate 3. j

Preferably the plaster board is providedground its margins with a border 25 that is at. g

In order to insure a tight and strong joint between .the several boards when fastened.

tothe structure,l the boards may be provided with a tongue-and-groove arrangement, the tongue 26 on one edge complementing the groove 27 `in the opposite edge, said tongue and groove being of any desired form.

It is particularly noted that thewedgeshaped cavities 5 securely hold the plaster in place even when said plaster is Wet and consequently very heavy and more or less plastic, and that the secure keying of the plaster may is effected by reason the plaster spreading out behind the face plate 2 much the same as it does behind the ordinary s pacedeapart lath, but at the same time the lndentatlons 4 hold the plaster that is forced back of said face plate so that'waste of the plaster can than when ordinary lathare employed .not occur as with the ordinary lath and yet' plaster in place is as secure of the lath, and'when sothe Waste of plaster becomes excessivfor'- the sharp edges of the metal severv the plaster and cause a great portion of the plaster. thatv down between'the Walls and become useless. It is obvious that various changes and modifications to the details of construction -be ma'de Without departing from the spirit of the invention. i

I claim v 1. A plaster board comprising a cement 'should hook over the backs of thelath tofall body having a-surface providedwith dovel i tail mortises, and a'face plate upon said surface providedv with' slits opening through said face plate t0 the dovetail mortises.`

2. A plaster board comprising a back plate, a face plate having slits' spacedin pairs, the portion of the plate between the adjacent slits ofeach pair being indented, and a body between and adhering to said plates. 3. A plaster plate 'on said surface having slits spaced inpairs, the portion yof the plate between the adjacent slits of each pair-being indented, and wires extending through said bodyand through the slits from mortise `to mortise-, said wires holding the, indented portions against the bottoms of the mortises'.

4. A plaster board comprising a body having a surface provided with dovetailed mor-v tises, said mortises being expanded at their bottoms and contracted'fat their inlets, and a face plate provided with slits adjacent the sldes of said mortises, the intermediate porf board comprising a body hav i ing a surface provided with mortise's, a face j tion of said face plate being indented into said mortises sot-hat plaster can enter sidewise through the slits and corneinto `contact with the exposed side portions of the body so as to strongly adhere thereto. 5. A plaster board comprising a body having a surface provided with mortises, a face plate on said surface having slits spaced in pairs, the portion of the plate between the adjacent slits of each pair being indented,

opeings, and wires extending through said 'a back plate on said body provided with -I body and through the slits from mortise to mortise, said wires holding the indented portions against the bottoms of the mortises and one end of each wire projecting from an edge of the plate and the other end of each wire being bent at right angles to the body part of the wire and projecting through the openings of the back plate.

6. A plaster board comprising a face plate provided with slits opening therethrough and spaced in pairs, the portion of the plate between the adjacent slits of each pair being indented to form vloops projecting from one side of said plate, a back plate, and a body between said face plate and back plate extending between the back and front plates and to the edges of said loops.

7. A plaster board comprising a face plate provided with slits opening therethrough and spaced in pairs, the portion of the plate between the adjacent slits of each pair being indented to form loops projecting from one side of said plate, a back plate, and a body between said face plate and back plate extending from plate to plate and to the edges of said loops between the pairs of slits and undercut at said edges.

8. A plaster board comprising a body having spaced apart dovetail keys, and a face plate indented intorthe spaces between the keys, said face plate being provided with slits in pairs extending along two edges of each of said indentations to expose the sides of said keys.

9. A plaster board comprising a body having a surface provided with dovetail mortises, and a face plate indented into said mortises and provided with slits extending along two edges of each indentation to expose the side walls of said mortises.

10. A plaster board comprising a face plate, a back plate, a body between said face plate and back plate, wires extending inside the body between said plates, terminals of some of said wires projecting from the edges of said plate and terminals of other of said wires projecting from the face of the back plate, said edge terminals being formed into eyes to afford fastening means to one another and the face terminals affording means to fasten to the ceiling rafters when the plaster boards are used for a ceiling.

11. A plaster board comprising a body, :2nd a face plate, said face plate being slitted and indented at alternate intermediate portions between the slits to form inserts having free longitudinal edges spaced apart from the edges of the intermediate portions.

12. A plaster board comprising a cement body having a surface provided with doveopes of this patent may be obtained for ve cents each, by addressing the insonne tail mortises, and a face plate upon said surface provided with perforations through said face plate to the dovetail mortlses.

13. A plasterboard comprising a body having a surface provided with dovetall morjtises, said mortises being expanded at their narrow openings in pairs extending along two edges of each of said indentations to expose the sides of said keys.

15. A plaster board comprising a body, and a-face plate, said face plate being perfoi-ated and indented at alternate intermediate portions between the perforations to form inserts having free longitudinal edges spaced apart from the edges of the intermediate portions.

.16. A plaster lath, embodying a cementi tions base and a form sheet therefor, said form sheet being perforated and the cementitious base having depressions extending to bottoms within the base, said depressions registering with said perforations, and on the side ofl which depressions the cementitious material of the base is exposed.

17. A plaster lath, embodying a cementitious base and a form sheet therefor, said form sheet being perforated and the cementitious base having depressions extending to bottoms within the base, said depressions registering with said perforation, and tongues integral with the form sheet attached thereto at one endat one side of the perforations and lying along the bottoms of the body depressions so as to cover the bottoms of the depressions and leave the cementitious material of the body exposed on ELMER T. GALLEY.

ln presence of* JAMES R. TowNsEND, GUsTAv- DREws.

Commissioner of latents,

Washington, D. G. 

